Needle plate device for a zigzag sewing machine

ABSTRACT

The needle bar of a zigzag sewing machine is set by manual operation of a knob to a central position, and to nonoscillation so that the reciprocating needle makes a straight seam. The same operation of the knob actuates a needle plate element to reduce the slot in the needle plate to a central opening for the passage of the needle so that the stitched fabric cannot be pressed into the slot by the reciprocating needle.

United States Patent [72] lnventors Susumu Hanyu Hachioji-shi; NoboruKasuga, Koganei-shi, Japan [21] Ap'pLNo. 755,971 [22] Filed Aug. 28,1968 [45] Patented Jan. 5, 1971 [73] Assignee Janome Sewing Machine Co.,Ltd.

Chuo-ku, Tokyo, Japan [3 2] Priority Aug. 29, 1967 [33] Japan [31 1 No.42/55,014

[54] NEEDLE PLATE DEVICE FOR A ZIGZAG SEWING 511 lnt.Cl D05b3/02 [50]Field ofSearch 112/158, 260, 157, 168

[56] References Cited UNITED STATES PATENTS v 1,290,924 l/l9l9 Davis112/260 3,358,631 12/1961 .Sharp 112/260 Primary Examiner-JordanFranklin Assistant Examiner-George V. Larkin Attorney-Michael S. StrikerABSTRACT: The needle bar of a zigzag sewing machine is set by manualoperation of a knob to a central position, and to nonoscillation so thatthe reciprocating needle makes a straight seam. The same operation ofthe knob actuates a needle plate element to reduce the slot in theneedle plate to a central opening for the passage of the needle so thatthe stitched fabric cannot be pressed into the slot by the reciprocatingneedle.

PATENTEU JAN 5197:

INVENTOR v Susana Musq lwegmu Mum BY 077448/ fr (p.

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SHEET 7 OF 9 INVENTOR 5 0314 ha HAM/y map/w mm BY flaw/mam ATTORNEY'PATENIEDJAN 51s 35521337 sum a are INVENT OR XML/w fl/wyl IUMOM/ mumATTORNEY NEEDLE PLATE DEVICE FOR A ZIGZAG SEWING MACHINE In a zigzagsewing machine, as is well known, a needle plate is provided with anelongated slot through which a needle passes when longitudinallyreciprocated as well as when transversely oscillated. Although such anelongated slot is indispensable in the zigzag sewing machine, it usuallytends to cause skipped stitches and also irregular seams during a sewingoperation especially when straight line stitching is performed with thezigzag sewing machine, since the sewn cloth is depressed into the slotbelow the level of the needle plate by the needle moving down. Suchdepression of the cloth is most conspicuous at the central part of theslot; where straight line stitching is usually performed with the needleposition being set at the center of the slot.

The primary object of this invention is to eliminate the above-mentioneddisadvantages and to enable the zigzag sewing machine to producebeautiful and perfect straight line seams.

In order to achieve such an object this invention provides that, whenthe needle bar is located in the right or left sewing position it isshifted to a predetermined position where it is not oscillated, whilethe elongated slot in the needle plate is partly closed to become a holejust suitable for straight line stitching operation. A single operatingmember controls both operations.

The other advantages and characteristics of this invention will beunderstood from the following explanation of actual embodimentsdescribed in reference to the attached drawings; in which FIG. 1 is afront elevational view of the entire sewing machine equipped with anembodiment of this invention.

FIG. 2 is a front elevational view of this embodiment with some partsillustrated in section and showing a condition in which the needle baris to be set for making the largest oscillation.

FIG. 3 is almost the same view as that of FIG. 2, however, showing acondition in which the needle bar is to be shifted to a predeterminedsewing position and set for making a straight reciprocating longitudinalmovement.

FIG. 4 is an exploded perspective view of this invention as illustratedin FIGS. 2 and 3.

FIG. 5 is a bottom view of this embodiment showing a plate element andother connecting members, the plate element opening the slot in theneedle plate for making zigzag stitching. 1

FIG. 6 is almost the same view as that of FIG. 5, showing the plateelement partly closing the slot ready for making straight linestitching.

FIG. 7 is an exploded perspective view of the embodiment as illustratedin FIGS. 5 and 6.

FIG. 8 is a top plan view of the needle plate according to thisinvention in which the slot in the needle plate is opened for zigzagstitching.

FIG. 9 is a sectional view taken along line lX-lX of FIG. 8.

FIG. 10 is a top plan view of the needle plate according to thisinvention in which the slot in the needle plate is closed for straightline stitching.

FIG. 11 is a sectional view taken along line Xl-Xl of FIG. 10.

FIG. 12 is a top plan view of the needle plate according to anotherembodiment of this invention in which the slot in the needle plate ispartly closed for straight line stitching.

FIG. 13 is almost the same view as that of FIG. 12 in which, the slot isopened for zigzag stitching.

FIG. 14 is an enlarged perspective view of the needle plate and theplate element of this invention.

Now referring to FIG. 1 in the machine frame 1 of the sewing machine, aswell known, a drive shaft 2 is rotatably journaled. The drive shaft 2 isat one end provided with a handwheel 3 and at the other end providedwith a balance crank and other members so that it may actuate a needlebar 5. Though not illustrated there is provided an oscillationgeneratingmechanism which is operatively connected to the drive shaft 2 and drivenby the same.

Referring to FIGS. 2 and 3 an oscillating member 11 is operativelyconnected to the oscillation-generating mechanism and oscillated by thesame. An oscillating rod I4 is at one end pivotally supported on aneedle bar support 18 by means of a pivot member 19 and at the other endportion connected to the oscillating member 11, so that the needle barsupport 18 may be oscillated in accordance with the oscillation of theoscillating member Ill against a leaf spring 20 which is at one endfixedly mounted at the front end of the machine frame 1 and normallyurges the needle bar support 18 to turn in one direction about a pivotI7. Thus the needle bar 5 which is reciprocably supported on the needlebar support 18 is transversely oscillated during its longitudinalreciprocating movement.

As illustrated in FIGS. 2-4 the oscillating rod 14 is at its right endconnected to the upper end of an oscillation-adjusting rod 16 by meansof a pivot element 15 while the oscillation-adjusting rod is at thelower end connected to one end portion of an adjusting arm 22 by meansof a pivot element 17. The adjusting'arm 22 with its hub 32 is turnablymounted on the shaft 28. The shaft 28 is arranged in the lower part ofthe casing of the sewing machine and projects at its forward end out ofthe casing for carrying an oscillation adjusting knob 21 thereon.Theoscillating member 11 is formed with a slide surface 13 slidinglyengaged by a pin 19 mounted at one end portion of the oscillating rod14, and the oscillating member 11 is turnably supported by a pivotelement 12 on aplate member 23 which is operated to change the sewingposition of the needle bar 5 as more clearly described hereinafter.Usually the pin 19 is slidingly moved along the slide surface 13 of theoscillating member 11 in the direction to and from the pivot element 12by turning the knob 21 so that the oscillating movement of the needlebar 5 may be varied by the oscillating rod 14.

A mounting plate 6 as illustrated in FIG. 1 mounts the knob 21 at itslower part outside of the casing. On the inside of the mounting plate 6,as illustrated in FIG. 4, a seat member 30 and a racked plate 31 arefixedly attached in a flatly joined condition by means of screws 92respectively passing through the holes 30'. Just below the seat member30 and the racked plate 31 a guide plate 29 is adjustably fixed by meansof screws 93 respectively passing through the elongated holes 29 formedin the guide plate. The guide plate 29 is at its one end portion formedwith a part 48 bent out of the plane of the guide plate, and adapted tobe engaged by a projection part 49 of the aforementionedoscillation-adjusting arm 22. The shaft 28 is at its inner end formedwith a reduced part 28' at which is fixed an oscillation regulatormember 39 with a hole 39" formed therein by means of a screw 97. On theforward part of the shaft 28, the oscillation-adjusting arm 22 with hub32, a washer 33, a setting member 36, a washer 34, a setting member 35and the manually operated oscillating-adjusting knob 21, which is on theoutside of the mounting plate 6, are aligned and fixed. A spring member51 surrounds hub 32 and has arms 52 and 53. The setting members 35, 36are at their upper parts respectively formed with upstandingelernents37, 38 which are adapted in a contacting condition to engage any of thedetaining places 31A of the racked plate 31, and further the settingmembers 35, 36 are provided with operating members 35 36 respectively.Such a pair of regulator set members is adapted, as illustrated in FIGS.2 and 3, to hold a bent extension 40 of the oscillation regulator member39 and detain it in its shifted position. The oscillation regulatormember 39 is normally urged to turn in the counterclockwise direction bya springl which is at one end attached to a projecting part 39 of thesame member 39 and at the other end anchored to the machine frame 1. Itis understood that when the bent extension 40 of the oscillationregulator member 39 is embraced by the pair of setting members 35, 36and detained at any desired position along the racked plate 31, it willbe detained there substantially by the left setting member 35 and serveto maintain constant a selected oscillating amplitude of the needle bar5.

FIG. 2 shows a condition of the apparatus in which the oscillationamplitude of the needle bar 5 is set to the maximum amplitude. The pivotelement 12 for the oscillating member 11 is inserted into the centralhub 43 of the aforementioned plate member 23 and tumably held there bymeans of a setscrew 93 which is threaded into the pivot element 12 onthe rear side of the plate member 23. As best .seen in FIG. 4, the platemember 23 is at one end tumably supported on the frame 1 by means of astepped screw 94 and at the other end engages a largest radius trackportion of a cam 25 which is fixedly mounted on a shaft 26. The shaft 26is provided with an operating knob 27 on its forward end which projectsout of the frame 1. The bent extension 40 of the oscillation regulatormember 39 is brought to the right side end of the racked plate 31 by theoscillationadjusting knob 21 manually turned in one direction, and heldthere by the setting members 35, 36. Consequently the pin 19 provided onthe oscillating rod 14 is slidingly moved to the position furthest fromthe pivot element along the slide surface 13 of the oscillatingmemberll. Thus the largest oscillating movement of the member about thepivot element 12 is .transmitted to the needle bar 5 through theoscillating rod 14.

FIG. 3 shows a condition of this. invention in which the needle bar 5 isshifted to a predetermined position and the oscillating movementeliminated, although the extension 40 of the oscillation regulatormember 39 is detained at the right side position of the racked plate 31just as illustrated in FIG; 2. According to the illustration of FIG. 3the pin 19 is shifted to the pivot element 12. from the position atwhich it is located as in FIG. 2 by rotating the cam 25 and a cam 42which are fixedly mounted on the shaft 26 and fixedly connected by meansof a screw 95 so that the two earns 25 and 42 may be rotated together byoperating knob 27 which is fixed on the forward end of the shaft, 26protruded out of the machine frame 1. The end part 24 of the platemember 23 engages the smaller radius track portion of the cam 25 whilethe projecting part '45 of an adjusting plate 100 engages the largestradius track portion of the cam 42. The adjusting plate 100 isadjustably fixed on a forked lever 44 by means of a stepped screw 83 anda screw 83' so that the position of the projecting part 45 of theadjusting plate 100 may be properly adjusted with respect to the cam 42.The forked lever 44 has a hub portion 44' turnably mounted on the frame1 by means of a pivot element 85, and is biassed by a spring member 86.The spring member 86 is mounted around the hub 44' the forked lever 44andat its one end abutting the forked lever 44 and at the other endanchored to the machine frame 1, so that the forked lever 44 is normallyurged to'turn clockwise and the projecting part 45 of the adjustingplate 100 is engaged with the cam 42. The forked lever 44 is at itslower portion provided with an oscillation control arm 46 and anactuating arm 54, the former-being adapted to engage a pin 47 which isfixed on the rear side of the oscillation-adjusting arm 22 and thelatter adapted to engage one end of a first layer which will bedescribed hereinafter.

As illustrated in FIG. 4 a U-shaped member 50 is adjustably attached tothe oscillation regulator member 39'by means of a screw 96 which passesthrough a slot 50" formed in the same member 50 and is threaded into thethreaded hole of the oscillation regulator member 39. The spring member51 is at its .one end attached to a part 50 of the U-shaped member50.and at the other end attached to the pivot element of the oscillationregulator arm 22. Since the part 50' of the U-shaped member'50 islocated on the upper edge 22" of the oscillation regulator ann 22,:themember 50 and the arm 22 are normally held together by the spring member51 as illustrated in FIG. 2.

When the knob 27 is rotated and the symbol S marked on the same knobcoincides with an index mark 90 on the frame 1 thereby to set the deviceas illustrated in FIG. 3, the forked lever 44 is turned clockwiseagainst the spring member 86 by the cam 42, and consequently theoscillation-control arm 46 of the forked lever 44 turns the oscillationregulator arm 22 in the counterclockwise direction against the action ofspring member 51 until the projectingpart 49 of the oscillationregulator arm 22 engages the-bent out part 48 of the guide plate 29andis stopped by the same. Accordingly the pin 19 mounted on theoscillating rod is slidingly moved along the slide. sur'- face 13 of theoscillating member 11 to the'pivot element 12 from the position shown inFIG. 2 by the oscillation-adjusting rod 16 and the needle bar 5 will notbe oscillatedsimultaheouslythe plate member 23 is turned to apredetermined position about the pivot element 94 due to the engagingrelation between the end part 24 of the plate member 23 and thecorresponding cam 25.,Consequently the oscillation center 12 of theoscillating member 11 is shifted togetherwith the plate member 23. Thusthe needle bar 5 is shifted to the center sewingjposition even if it waslocatedin the right or-left sewing or field position, since theoscillating rod 14 is always subjected to the biasing force of springmember 20 so that it may a'tits pin 19 engage the slide surface 13 oftheoscillating member 11. In this manner, the central sewing fieldposition of needle bar 5 with the needle is set by the device 23, 24,25, 94, while oscillation of the needle bar is stopped by the device44,,42, 46, 22, 51, 29, 19-, 13,11, 12. Knob27 controls bothmaperations.

Referring to FIGS. 5, 6 and 7, as is already describednthe actuating arm54 of the forked lever 44 normally engages one end-57 of the firstlever56 which is at its central portion tumably supported on the rearsurface of the machine bed 7 by means of a pivot element 55. The'otherend 58 of the first lever 56 is connected to a connecting part'6l formedat one end of a second lever 60 by means of a-stud 98. The second lever60 is composed of members'60a and 60b, and tumably supported on the rearsurface of the-machine bed 7. The members 60a and 60b areadjustablyconnected to each other by the above mentioned pivot'element59a'nd a screw 99 so that both members may be together actuated. A stop88 is adjustably attached to the second lever 60 by means of a screw 89and adapted to engage the projection 84 of the machine bed 7 so that itmay serve to prevent the second lever troni being displaced too far. Theother end 62 of the second lever 60 engages one end portion of a thirdlever 64 which is turnablysupported onthe rear surface of the needleplate 71 by means of a pivot element 63. Since the second lever 60 isbiassed to turn clockwise about the pivot element 59 by a spring 79which is at one end attached to the end portion 61 of the lever 60 andatthe other end anchored to the machine bed 7, the second lever 60engages at its end 62 the end 65 of the third lever64. The third lever64 is provided with a transverse ly elongated hole 67 between thepivotelement 63 and the end portion 65 thereof. The hole 67 fittedlyreceives a projection 68 from a plate element 66 as illustrated .inFIGS. 9 and 11. The third lever 64 is biassed to turn clockwise aboutthe pivot element 63 by a spring 70 which isat one end attached to theother end portion 69 of lever 64 and at the other end anchored to themachine bed 7. Thus the plate element 66 is biassed for-i ward towardthe elongated slot 77 formed in the needleplate' 71. Howeverthe actionof the spring '78 is normally nullified" by the opposing action ofspring 79 which is of stronger ten? sion. As shown in FIGS. 8 and 10 theneedle plate 71 is mounted in the top surfaceof the machine bed 7 bymeans of:

screws 72, 73, and is at itscentral part formed with elongated cutouts76 in which feed dogs are'located so that they may perform the movementsrequired for feeding the cloth or any other material to be sewn, andfurther the needle plate 71 is formed with the above-mentioned elongatedslot 77 for allow ing the passage of the reciprocating as' well asoscillating nee dle 119. Adjacent the needle plate 71 a slide plate- 74is; slidingly fitted in the machine bed 7. The plate element 66 isslidably fitted into a groove of the needle plate 71 and has a. topsurface flush with the top surface of the same. Plate ele'f ment 66 hastwo fingers 66a forming a rectangular cutout 80' in which a projection81 of the needle plate 71 is located, whose top surface is also flushwith the top surface of the needle plate 71. Projection 81 is locateddirectly adjacentone' lateral edge of slot 77 and forms the central partofthesame. When plate element 66 is in the retracted positionshown inFIG. 8, the end faces of fingers 66a extend along the outer portions ofthe same lateral edge of slot 77. When plate element 66 is shifted tothe position of F I6. 10, fingers 66a close the outer portions of slot77 so that only a small opening 80 at the center of slot 77 remains openfor the passage of the longitudinally reciprocating needle. Plateelement66 can be moved until the bottom of cutout 80 abuts projection 81 whichbounds central opening 80' together with fingers 66a. When the plateelement 66 is retracted to the position of FIG. 8, faces of projection81 and of fingers 66a bound the lateral edge of slot 77 which is nowagain free for the transversely operating and longitudinallyreciprocating needle. Another embodiment of this invention is shown inFIGS. l214. According to this embodiment the plate element 66' is made.as thin as possible, and the cutout 82 is made as small as possiblewith an arc-shaped edge only to allow the passage of the needle. Whenthe plate element 66' slides forward the slot 77 is closed by it andchanged to a central opening 82, and when the plate element 66' isretracted the slot 77 is none the less suitable for zigzag stitchingsince the cutout 82 is as stated above very small and shallow and willnot permit depression of the cloth. I c

As understood from the foregoing description, this inventionprovidessimultaneous cooperation of a device for controlling the sewingposition of the needle bar, a device for controlling the oscillatingmovement of the needle bar and a slot for controlling the needle platedevice, so that a zigzag sewing machine may perform a perfect straightline stitching,

.We claim:

1. In a zigzag sewing machine comprising a machine bed, a needle barhaving a needle, a first device for controlling the oscillating movementof said needle bar and needle, and a second device for controlling thesewing field position of said needle bar, in combination, a needle platedevice comprising a needle plate formed with an elongated slot for thepassage of said needle during zigzag stitching and mounted on saidmachine bed, a plate element slidably mounted on said needle plate formovement to and from a position partly closing said slot so that only anopening for the passage of said needle during straight stitching remainsopen, operating means controlling said first and second devices andincluding a manually operated dial and first and second cams, and levermeans connecting said operating means with said plate element andincluding a forked leverand first, second, and third levers.

2. Needle plate device as set forth in claim 1 comprising a followermember connected withv said second device and cooperating withsaid firstcam, and an adjusting plate connected with said first device andadjustably mounted on said forked lever, and cooperating with saidsecond cam.

3. A needle plate device as set forth in claim 2 wherein said forkedlever is formed with an oscillation control arm and an actuating arm,the former beingadapted to control the oscillating movement of theneedle bar and the latter adapted to actuate said first, second andthird levers.

4. A needle plate device as set forth in claim 1 wherein a projection isformed on said needle plate adjacent to said elongated slot, and acutout is formed at one end of said plate element so that said cutoutmay slidably engage said projection and said plate element may be guidedby said projection during its sliding movement.

5. A needle plate device as set forth in claim 4 wherein said plateelement is at its one end formed with a hole just for straight linestitching;

6. A needle plate device as set forth in claim 3 wherein said forkedlever operatively actuates said first, second and third levers toslidingly move said plate element.

7. A needle plate device as set forth in claim 6 wherein said secondlever is composed of two members for adjustably obtaining a correctpredetermined movement of said plate element. 1

8. In a zigzag sewing machine including a needle bar and a needlereciprocable in longitudinal direction for 'making stitches forming astraight seam, and oscillatable in a transverse direction for maklngzigzag stitches, in combination, a

device for controlling the oscillating movement of said needle bar andneedle; a needle plate formed with a transverse slot for the passage ofsaid needle during oscillation and zigzag stitching; a plate elementmounted on said needle plate for fect nonoscillation and straightstitching of said needle bar and needle, and positioning of said plateelement in said operative position whereby a fabric on said'needle plateand needle element cannot be pressed into said slot during straightstitching. 9. In a zigzag sewing machine as claimed in claim 8, incombination, another device for controlling the sewing field position ofsaid needle bar and needle; wherein said manually operated means isconnected with said other device for setting said needle bar and needleto a central field position simultaneously with the placing of saidplate element in said operative position and with the setting of saidneedle bar to straight stitching; and wherein said plate element in saidoperative position covers the ends of said slot and has a central cutoutregistering with said slotin said operative position and forming

1. In a zigzag sewing machine comprising a machine bed, a needle barhaving a needle, a first device for controlling the oscillating movementof said needle bar and needle, and a second Device for controlling thesewing field position of said needle bar, in combination, a needle platedevice comprising a needle plate formed with an elongated slot for thepassage of said needle during zigzag stitching and mounted on saidmachine bed, a plate element slidably mounted on said needle plate formovement to and from a position partly closing said slot so that only anopening for the passage of said needle during straight stitching remainsopen, operating means controlling said first and second devices andincluding a manually operated dial and first and second cams, and levermeans connecting said operating means with said plate element andincluding a forked lever and first, second, and third levers.
 2. Needleplate device as set forth in claim 1 comprising a follower memberconnected with said second device and cooperating with said first cam,and an adjusting plate connected with said first device and adjustablymounted on said forked lever, and cooperating with said second cam.
 3. Aneedle plate device as set forth in claim 2 wherein said forked lever isformed with an oscillation control arm and an actuating arm, the formerbeing adapted to control the oscillating movement of the needle bar andthe latter adapted to actuate said first, second and third levers.
 4. Aneedle plate device as set forth in claim 1 wherein a projection isformed on said needle plate adjacent to said elongated slot, and acutout is formed at one end of said plate element so that said cutoutmay slidably engage said projection and said plate element may be guidedby said projection during its sliding movement.
 5. A needle plate deviceas set forth in claim 4 wherein said plate element is at its one endformed with a hole just for straight line stitching.
 6. A needle platedevice as set forth in claim 3 wherein said forked lever operativelyactuates said first, second and third levers to slidingly move saidplate element.
 7. A needle plate device as set forth in claim 6 whereinsaid second lever is composed of two members for adjustably obtaining acorrect predetermined movement of said plate element.
 8. In a zigzagsewing machine including a needle bar and a needle reciprocable inlongitudinal direction for making stitches forming a straight seam, andoscillatable in a transverse direction for making zigzag stitches, incombination, a device for controlling the oscillating movement of saidneedle bar and needle; a needle plate formed with a transverse slot forthe passage of said needle during oscillation and zigzag stitching; aplate element mounted on said needle plate for movement between aninoperative position in which said slot is open, and an operativeposition partly closing said slot so that only an opening for thepassage of said needle during straight stitching remains open; andmanually operated means connected with said device for controlling theoscillating movement and with said plate element to simultaneouslyeffect nonoscillation and straight stitching of said needle bar andneedle, and positioning of said plate element in said operative positionwhereby a fabric on said needle plate and needle element cannot bepressed into said slot during straight stitching.
 9. In a zigzag sewingmachine as claimed in claim 8, in combination, another device forcontrolling the sewing field position of said needle bar and needle;wherein said manually operated means is connected with said other devicefor setting said needle bar and needle to a central field positionsimultaneously with the placing of said plate element in said operativeposition and with the setting of said needle bar to straight stitching;and wherein said plate element in said operative position covers theends of said slot and has a central cutout registering with said slot insaid operative position and forming said opening in the center portionof said slot.
 10. A zigzag sewing machine as claimed in claim 9 whereinsaid needle plate has a projection located in said cutout of Said plateelement adjacent a transverse edge of said slot, said projection guidingsaid plate element for movement between said inoperative and operativepositions and stopping the same in said operative position.
 11. A zigzagsewing machine as claimed in claim 9 wherein said manually operatedmeans includes a dial knob, and linkage means connecting the same withsaid devices and said plate element.